Sterile insect technique (SIT) in the near east — a transboundary bridge for development and peace

Mediterranean fruit fly, Ceratitis capitata (Wied.), is a major pest of fruits and vegetables throughout the region, reduces yield of marketable fruit and limits exports. The Arava Medfly Eradication Project (AMEP) was initiated in 1997, and serves as a pilot effort to begin implementing the sterile insect technique in the Near East. It could become a model for future implementation of the proposed EASTMED project, a plan conceived and planned by the International Atomic Energy Agency in 1994–1995 with input of regional experts. The target area lies in the Arava Valley between the Dead Sea and the Red Sea. AMEP activities include host mapping, population monitoring and suppression followed by weekly releases of sterile flies. This project will lead to permanent establishment and maintenance of Medfly free areas. In addition, new technologies are being tested under local conditions. This includes use of tsl male-only strains of medflies, aerial releases with a chilled insect release machine, female attractants and new trap designs. At present, the project relies upon long-distance shipping of pupae from Madeira, Portugal and Guatemala rather than local sources. The medfly population on the Israeli side of the Arava valley, was monitored in 132 trimedlure loaded traps. It dropped by July 1999 to 0.04 flies per trap per day from the pre-eradication level of 0.71 flies per trap per day in July 1998. In June 1999, only 19% of the traps captured wild flies as compared to 40% of the traps in June 1997. As medfly does not respect international boundaries, transboundary co-operation is a key factor for successful implementation. Current project status and plans for future expansion within Israel, Jordan and the Palestinian Authority will be presented.     

Characterization of segregation distortion on chromosome 3 induced in wide hybridization between indica and japonica type rice varieties

We previously surveyed chromosomal regions showing segregation distortion of RFLP markers in the F₂ population from the cross between a japonica type variety ‘Nipponbare’ and an indica type variety ‘Milyang23’, and showed that the most skewed segregation appeared on the short arm of chromosome 3. By comparison with the marker loci where distortion factors were previously identified, this region was assumed to be a gametophytic selection-2 (ga2) gene region. To evaluate this region, two near isogenic lines (NILs) were developed. One NIL had the ‘Nipponbare’ segment of this region on the genetic background of ‘Milyang23’ (NIL9-23), and the other NIL had the ‘Milyang23’ segment on the genetic background of ‘Nipponbare’ (NIL33-18). NIL9-23 and ‘Milyang23’, NIL33-18 and ‘Nipponbare’, and ‘Nipponbare’ and ‘Milyang23’ were respectively crossed to produce F₁ and F₂ populations. The F₁ plants of NIL9-23 × ‘Milyang23’ and NIL33-18 × ‘Nipponbare’ showed high seed fertility and the same pollen fertility as their parental cultivars, indicating that ga2 does not reduce seed and pollen fertility. Segregation ratio of a molecular marker on the ga2 region in the three F₂ populations was investigated to clarify whether segregation distortion occurred on the different genetic backgrounds. Segregation distortion of the ga2 region appeared in the both F₂ populations from the NIL9-23 and ‘Milyang23’ cross (background was ‘Milyang23’ homozygote) and the ‘Nipponbare’ and ‘Milyang23’ cross (background was heterozygote), but did notin the F₂ population from the NIL33-18 and ‘Nipponbare’ cross (background was ‘Nipponbare’ homozygote). This result indicates that ga2 interacts with a ‘Milyang23’ allele(s) on the different chromosomal region(s) to cause skewed segregation of the ga2 region. In addition, segregation ratio was the same between the F₂ populations from NIL9-23 × ‘Milyang23’ and ‘Nipponbare’ × ‘Milyang23’ crosses, suggesting that the both genotypes, ‘Milyang23’ homozygote and heterozygote, of gene(s) located on the different chromosomal region(s) have the same effect on the segregation distortion. This revised version was published online in July 2006 with corrections to the Cover Date.     

杜仲杂种优良无性系抗旱性间接评价

以7个杜仲无性系22-22、2-23、4-30、17-17、2-32、6-30、5-152和2个对照品种（无性系）秦仲2号（Qinzhong No.2）、龙拐（Longguai）为对象,以其2年生嫁接苗成熟叶片为材料,采用常规石蜡切片法研究叶片解剖结构、扫描电镜技术观察气孔结构和压力室技术测定水分生理指标,用主成分分析法筛选主要指标,用隶属函数法对各无性系抗旱性进行对比分析。结果表明,共筛选出栅栏组织厚度、原初渗透势、气孔开度、厚角组织厚度4项主要指标,12项解剖结构参数、5项水分生理指数和5项气孔参数,均在无性系间差异显著,无性系抗旱性排序为:6-30>4-30>龙拐>秦仲2号>17-17>5-152>22-22>2-23>2-32。研究结果可对进一步筛选杜仲优良无性系提供参考依据。     

Crustal architecture of the cascadia forearc

Seismic profiling data indicate that the thickness of an accreted oceanic terrane of Paleocene and early Eocene age, which forms the basement of much of the forearc beneath western Oregon and Washington, varies by approximately a factor of 4 along the strike of the Cascadia subduction zone. Beneath the Oregon Coast Range, the accreted terrane is 25 to 35 kilometers thick, whereas offshore Vancouver Island it is about 6 kilometers thick. These variations are correlated with variations in arc magmatism, forearc seismicity, and long-term forearc deformation. It is suggested that the strength of the forearc crust increases as the thickness of the accreted terrane increases and that the geometry of the seaward edge of this terrane influences deformation within the subduction complex and controls the amount of sediment that is deeply subducted.     

Biaxial Extensional Viscosity of Sheeted Noodle Dough

The flows encountered during the sheeting process contain a more extensional component and more stretching than simple shear. Evaluating the properties of the extensional rheological flow of wheat flour dough is essential to better understand the sheeting process and the final quality of the product. Our results show that the curves of biaxial extensional viscosity versus extensional strain rate for dough from different wheat cultivars including Dark Northern Spring (DNS), Hard Red Winter (HRW), and Western White Wheat (WW) with protein contents of 7.81–18.09% and water contents of 32–40% could be discriminated. During a lubricated compression test, the sheeted dough displayed a region of extensional thickening followed by a region of mild extensional thinning, giving rise to an s-shaped extensional stress-strain rate curve. The higher degree of extensional thinning was exhibited for the sheeted dough prepared from the flour of DNS and HRW wheat mixture with an extensional thinning index of n = 0.65–0.74; while the lower degree of extensional thinning was displayed for the DNS wheat with an extensional thinning index of n = 0.89–0.96. The data of biaxial extensional viscosity (η_Bmax) versus water content and protein content could be described by power relationships. The results suggest that biaxial extensional viscosity can be a useful modeling and process design parameter that objectively represents the rheological properties during dough sheeting.     

Dietary calcium requirement and effects on growth and tissue calcium content of juvenile grass carp (Ctenopharyngodon idella)

A growth trial was conducted to estimate the optimum concentration of dietary calcium (Ca) for grass carp (Ctenopharyngodon idella). Triplicate groups of grass carp (4.52 ± 0.02 g) were fed diets containing graded levels (2.75, 4.51, 6.24, 7.99, 9.66 and 11.5 g kg^?1) of Ca for 8 weeks. Weight gain, feed efficiency and protein efficiency ratio were linearly increased up to the 7.99 g kg^?1 dietary Ca and then maintained stable beyond this level (P < 0.05). Dietary Ca levels higher than 7.99 g kg^?1 significantly increased the ash contents of whole body, vertebrae and scales. Ca contents in whole body, vertebrae and scales were linearly increased up to the 7.99 g kg^?1 dietary Ca and then maintained stable beyond this level (P < 0.05). In contrast, dietary Ca levels higher than 9.66 g kg^?1 significantly decreased Mg contents in whole body, vertebrae and scales. Dietary Ca levels higher than 7.99 g kg^?1 significantly increased plasma alkaline phosphatase activity. However, plasma Ca, P and Mg contents were not significantly affected by dietary Ca supplements (P > 0.05). Polynomial regression analysis indicated that 10.4 g kg^?1 dietary Ca was required for maximal tissue storage and mineralization as well as optimal growth.     

Seroprevalence of Mycobacterium avium subspecies paratuberculosis, Neospora caninum, Bovine leukemia virus, and Bovine viral diarrhea virus infection among dairy cattle and herds in Alberta and agroecological risk factors associated with seropositivity

A province-wide, cross-sectional seroprevalence and agroecological risk factor study of Mycobacterium avium subspecies paratuberculosis (MAP), Neospora caninum (NC), Bovine leukemia virus (BLV), and Bovine viral diarrhea virus (BVDv) genotypes 1 and 2 (BVDv1 and BVDv2) infection in dairy cattle herds in Alberta was conducted. Among adults, the seroprevalence of MAP, NC, and BLV was 9.1%, 18.5%, and 26.9%, respectively. For MAP, based on a herd test cutpoint of 2 or more seropositive cows, 58.8% of herds were infected. Herd-level seroprevalence for NC and BLV was 98.7% and 86.7%, respectively, based on a herd-test cutpoint of 1 seropositive cow. Among unvaccinated dairy heifers, the seroprevalence for BVDv1 and BVDv2 infection was 28.4% and 8.9%, respectively, while herd-level infection was 53.4% and 19.7%. Seroprevalence for MAP varied moderately by agroecological region, whereas that for NC, BLV, and BVDv1 and BVDv2 did not. For MAP, aridity and soil pH (correlated features of the region) were also important.     

Antibody response to toxic shock syndrome toxin-1 of Staphylococcus aureus in dairy cows

Antibody response to toxic shock syndrome toxin-1 (TSST-1) of Staphylococcus aureus in dairy cows was examined by enzyme linked immunosorbent assay (ELISA). Serum antibody to TSST-1 was not detected in 39 (76.5%) of 51 calves, which were 1-6 months of age. In contrast, TSST-1 antibody was demonstrated in 1728 (72.6%) of 2380 lactating cows housed on 36 dairy farms. The ELISA values of antibody ranged from 0.2 to 3.0 OD and presented a distribution with the peak at 1.6 OD. The mean ELISA value differed between farms, and it increased slightly along with parturient history. Somatic cell counts of milk from 174 lactating cows was compared with TSST-1 antibody and tst1,000,000 cells per ml. The mean ELISA values in milk were lower than those of sera, but they rose as somatic cells increased. The tst gene of S. aureus detected in 76.0-86.2% of the milk samples containing somatic cells > 500,000 cells per ml, a level which indicates mastitis. The data suggests that many lactating cows may be infected by TSST-1- producing S. aureus.     

Effect of dietary selenium source, level, and pig hair color on various selenium indices

The first experiment evaluated the effects of feeding various levels of Se, two Se sources, and hair color on selenosis responses in growing-finishing pigs. The study conducted in two replicates was a 2 x 6 x 2 factorial arrangement in a split-plot design. Sodium selenite and Se-enriched yeast added at 0.3, 1, 3, 5, 7, and 10 ppm Se served as the main plot and pig hair color as the subplot. A total of 96 crossbred pigs were allotted and fed their treatment diets for a 12-wk period. White and dark (red or black) hair samples were collected from the dorsal-midline at the 4-, 8-, and 12-wk periods from one pig of each hair color from each treatment pen. Lower pig weights (P < 0.10) and daily gains (P < 0.05) occurred as dietary Se level increased when pigs were fed either Se source. Selenosis responses were somewhat more severe, when the inorganic Se source was fed. Alopecia and hoof separation were encountered after the 8-wk period when pigs were fed inorganic rather than organic Se. Plasma Se increased as dietary level increased (P < 0.01), when organic Se was provided (P < 0.01), and was higher (P < 0.05) when pigs were white-haired. A time x hair color x dietary Se level interaction (P < 0.05) occurred, in which hair Se concentration was higher in dark- than in white-colored pigs and increased as dietary Se level increased as the experiment progressed. The correlation coefficient between dietary Se level and hair Se concentration averaged 0.90 (P < 0.01). Cysteine was the amino acid in the highest concentration in hair, but this and other amino acids were not affected by Se level, Se source, or hair color. A second experiment was a 3 x 6 factorial arrangement in a split-plot design with three 9-mo-old gilts from each of the Yorkshire, Duroc, and Hampshire breeds to determine whether hair Se concentration differed by body location and breed. Hair samples were collected from the shoulder, back, rump, front-leg, belly, and hind-leg areas. Hair Se concentration was higher in red- and white-haired pigs and lower in black-haired gilts (P < 0.01). Higher hair Se concentrations (P < 0.05) occurred from the lower than from the upper body areas. Our results suggest that selenosis occurs at dietary levels > 5 ppm and that white-haired pigs exhibit alopecia sooner than dark-haired pigs. No difference in hair Se concentration occurred when diets were < 1 ppm Se, but as dietary Se level increased dark-haired pigs retained more Se in their hair than white-haired pigs.